The blaze also prompted a rare call-up for hundreds of military reservists to join overstretched police and firefighters.

Authorities speculated that the blaze may have been started by politically-motivated arsonists.

Spreading quickly due to dry, windy weather, the fire raced through Haifa's northern neighbourhoods. While there were no serious injuries, several dozen people were taken to hospital for treatment for smoke inhalation.

Police and firefighters were deployed throughout the city, as people loaded up supermarket trolleys with belongings and fled their homes. Some people connected hoses together from apartment buildings to help battle the fires, while residents held cloths over their faces.

Israeli's police chief, Roni Alsheich, told reporters that arsonists were suspected of setting some of the fires and that arrests had been made.

"It's safe to assume that whoever is setting the fires isn't doing it only out of pyromania," he said. "It's safe to assume that if it is arson it is politically-motivated."

The blaze was the largest of several fires to erupt across the country in recent days.

The rash of fires is the worst since 2010, when Israel suffered the single deadliest wildfire in its history. That blaze burned out of control for four days, killed 42 people and was extinguished only after firefighting aircraft arrived from as far away as the United States.

Israel has strengthened its firefighting capabilities since then, buying special planes that can drop large quantities of water on affected areas. Several countries, including Russia, Cyprus, Turkey, Croatia and Greece - were also sending assistance to battle this week's blazes.

Guy Catlan, who runs a petrol station in Haifa, said that workers turned the power off and were helping firefighters to prevent the flames from reaching it.

"There is a very large quantity of fuel here, it is very dangerous to the entire area, it could be a big catastrophe," he said.

Residents of eight neighbourhoods in the northern city of Haifa were told to evacuate their homes on Thursday afternoon, police spokesman Micky Rosenfeld said. Or Doron, a spokeswoman for the city of Haifa, said some 50,000 people had been evacuated.

Michal Schanin, a professor at the University of Haifa, was in the middle of a lecture when she received word that she and her 70 students would need to evacuate. She said that while the evacuation was orderly, the flood of cars fleeing the area caused a traffic jam.

"We couldn't move. If, God forbid, there would have been fire there it would have been one huge trap," she said.

The military said it deployed two search and rescue battalions in order to assist civilian efforts. It also called up about 500 reserve soldiers to back up the police and fire departments.

Prime Minister Benjamin Netanyahu meanwhile spoke with Russian President Vladimir Putin, thanking him for his help in dealing with the fires. The premier's office said that Russia is sending two large firefighting aircraft to Israel.